The present invention relates to a casting tube of refractory material which, at its upper end, comprises openings for the injection of a protective gas to prevent oxidation of the molten metal and to cool the walls of said casting tube. More particularly, the invention relates to a casting tube provided with openings for the injection of a protective gas having a particular shape and arrangement.
The present invention is used widely in the continuous casting of steel during which the steel is discharged from a casting ladle into a degassing chamber or into a basket and from there into a mould or into an ingot mould.
The duration of the casting operation and the large contact surface which the metal presents to the air makes it essential to use means establishing a protective atmosphere to protect all the exposed surfaces of the metal against oxidation,